AD/DHC-1/34 Amdt 2 Shock Absorber Strut Piston Tube (Cth)

AIRWORTHINESS DIRECTIVE

On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/DHC-1/34 Amdt 1 and issues the following AD under subregulation 39.001(1) of CASR 1998.  The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

De Havilland DHC-1 (Chipmunk) Series Aeroplanes

AD/DHC-1/34 Amdt 2 Shock Absorber Strut Piston Tube 12/2011

Applicability:

English production (C1), all models, and Portuguese (T Mk 20) production models.

Requirement:

Inspect in accordance with British Aerospace Technical News Sheet (TNS) No.194 Issue 2.

Note 1:  TNS 194 provides details of BAe field support with regard to sample collection or chemical analysis services etc. to comply with the requirements of this Directive.  Local NATA testing laboratories are also able to carry out the chemical analysis requirement.  A copy of BS T60 is available on request to the Authority through a District Airworthiness Office.

Note 2:  UK CAA AD 004-02-95 refers.

Compliance:

Unless already accomplished, before further flight.

This Amendment becomes effective on 21 June 2011.

Background:

A case has been found of an unapproved main undercarriage piston tube of unknown origin being fitted to an aircraft.  The item was of incorrect material and gauge.

This inspection was introduced in 1995, and up until now, Australia has had no Portuguese manufactured Chipmunks on the register, hence the CASA AD has only been effective for English production Chipmunks.

This amendment is to include the Portuguese manufactured Chipmunk in the applicability for this AD, as a recent review shows that this inspection is also applicable to the Portuguese model (T Mk 20).

There is no change to the requirements.  The TNS specifies compliance within 12 months of the issue date of the TNS.  Since this date is well past, all aircraft (including recently imported or about to be imported aircraft) must comply before further flight.

Amendment 1 was issued in 1997 in response to a new UK CAA AD which requires certain actions because cases have been found of undercarriage piston tubes being manufactured from material of incorrect specification.  Piston tubes have also been found to have suffered from corrosion, both internally and externally.

Glen Steemson
Delegate of the Civil Aviation Safety Authority

15 June 2011